Power consumption is a major concern for Linux users. If you're using Linux in the server room, reduced power consumption can save a lot of money. If you're using Linux on a laptop, better power management means longer battery life. Likewise, when using Linux in devices, power consumption is all-important. The release of PowerTOP 2.0, then, is of interest to almost all Linux users.
PowerTOP is a tool that can be used to diagnose problems with power management and consumption. In addition, it can be used to tweak power management settings on Linux, to help provide better power performance. Not sure if the problem is software or hardware? PowerTOP can help with that.
What's New in 2.0?
PowerTOP was already pretty nifty, but the 2.0 release pushes it over the... top.
With 2.0, PowerTOP adds support for CPU idle, frequency and power traces. According to the release notes, this means that PowerTOP now "gives a clearer picture of how programs affect CPU utilization, and the impact on important power-saving sleep states."
Another feature in the 2.0 release is system device tracking. This lets developers and users see if any devices used on the system are "problematic in terms of power behavior."
PowerTOP 2.0 sports a new "interactive" mode that has a tab-based interface and real-time visualization of your power data. The data is split up into an overview, idle stats, frequency stats, device stats, and "Tunables." Tunables might sound like a treat for your cat, but it's actually a view that lets you see and change the system's power options.
The reporting mode (or non-interactive mode) can be used to produce HTML and CSV reports. You can use the CSV data to plug into a spreadsheet to analyze trends over time.
This release has limited support for compiling for Android, which is no doubt an important target for many manufacturers working with Android. See the README for more information on Android.
PowerTOP 2.0 is on GitHub if you want to pull the source code. Don't use GitHub to send patches, though. That's still done on the mailing lists.
Compiling PowerTOP is pretty simple, but you will need to have several kernel configuration options enabled to get it to work properly. Again, see the README for the full list. You'll probably want a 3.0 or later kernel, at a minimum. You'll also need
libstdc++, and several development packages.
As nifty as PowerTOP 2.0 is, you can expect much more in the future. According to the release notes, "you can expect more great changes, and more interactivity. We have plans, ideas, and a newly restored vigor towards PowerTOP. We will be planning iterative releases, giving blog updates, and talking contributions, not only in code, but QA, documentation, and functional suggestions (especially if the submitter is willing to also code on his/her functional suggestions). We don't have a lot of dedicated resources, but we now have more than we've ever had before."
This is great news for Linux users, expect to see even better power performance out of your Linux systems in the coming months as developers have better tools to work with.